ANTIBIOTICS 185 



exceptions being Botrytis cinerea and Helminthosporium 

 avence against Staph, aureus and Fusarium javanicum 

 against E. coli. 



Among the number of antibiotics recently isolated 

 and about which little is kno^^'n at present the following 

 may be mentioned. Allicin, from garlic, Allium sativum, 

 probably having the structure 



which is active against Gram -positive and Gram -negative 

 organisms ; bacitracin, from a B. subtilis like organism, 

 which is non -toxic to animals but is very active against 

 Group A h^emolytic streptococci, staphylococci and the 

 gas gangrene organisms ; mycophenolic acid (see p. 296), 

 formed by Penicillium hrevi-compactum, which inhibits 

 staphylococci, streptococci, C. diphtherice, B. subtilis 

 and many pathogenic fungi but not Gram -negative 

 organisms ; viridin, from Trichoderma viride, which is 

 inhibitory to the growth of Botrytis, Fusariiun, Tricho- 

 thecium and Cephalosporium strains and to a less extent 

 to that of Penicillium and Aspergillus strains ; a sub- 

 stance formed by Group N streptococci Avhich inhibits 

 many Gram -positive organisms, including streptococci. 

 Bacillus, Clostridium and Lactobacillus species ; subtilin, 

 from B. suhtilis, active against Gram-positive but not 

 against Gram-negative organisms ; violacein, the pigment 

 from Chr, violaceum (see p. 389), which is very inhibitory 

 to Gram -positive organisms (meningococcus, the only 

 Gram -negative organism affected, is inhibited by 0-0005 

 per cent, of violacein), Saccharomyces cerevisice and some 

 moulds. 



It is interesting that the basic proteins, protamine 

 and histone, which are of comparatively low molecular 

 weight, are bacteriostatic or bactericidal to E. typhosa, 

 Shigella jmradysentericE, E. coli, B. suhtilis, Staph, alhus, 

 Staph, aureus, CI. ivelchii, CI. tetani, CI. histolyticiuti, 



